During the use of the cooling fan, the influence of humidity on the life of the fan cannot be ignored. Especially in industrial and household appliances, such as air conditioning cross-flow fans, cross-flow cooling fans and metal cross flow fans, humidity will not only affect the efficiency of heat dissipation, but also may adversely affect the internal structure of the fan. How does humidity affect the life of the cooling fan? High humidity environments pose multiple challenges to the motors, bearings and metal components inside cooling fans. High humidity may cause internal fan components to rust or corrode. In particular, fans with metal shells or internal components, such as metal cross flow fans, are more susceptible to humidity.     Chungfo's way of coping In order to deal with the potential threat of humidity to the life of the fan, Chungfo strictly selects moisture-proof and rust-proof materials in the design and manufacturing process of the fan. For example, Chungfo's cross flow fan in air conditioners pay attention to corrosion resistance in the selection of materials, and have passed a number of humidity tests to ensure their long-term operation in high-humidity environments such as air conditioning equipment. Our cross-flow cooling fans are also designed with a moisture-proof seal structure, which effectively prevents moisture from entering the motor part, further extending the life of the fan.     Humidity has a profound impact on the life of cooling fans, especially for products such as metal cross-flow fans, cross flow cooling fans and air conditioning cross-flow fans that are exposed to high humidity for a long time. By selecting high-quality anticorrosive materials and conducting rigorous humidity life testing, Chungfo provides customers with more durable and reliable cooling fan products.

Introduction Today, bridge mills are an indispensable tool for manufacturers in industries like aerospace, automotive, energy, and heavy machinery. Bridge mills are increasingly used as engineering designs become more complex and the need for enhanced stability, precision and flexibility to machine large and heavy workpieces to extremely tight tolerances continues. As a rigid overhead bridge structure with multi axis capabilities, bridge mills offer high precision cutting compared to traditional knee mills or gantry mills. In this article, we will look at how bridge mills can produce continuous production of complex components that can’t be made with smaller machines. Whatever your R&D work or high volume manufacturing needs, bridge mills provide a flexible solution to maximize productivity and minimize errors.   What is a Bridge Mill? A bridge mill uses a huge overhead bridge assembly to support the spindle and worktable instead of a column or gantry. The spindle is held as it moves in X, Y, and Z axes by the bridge as a rigid support arm and the worktable below is positioned relative to the cutting tool. This overhead arrangement leaves the entire area beneath the bridge open for oversized parts and assemblies, allowing much larger workpieces than could fit on a traditional vertical mill. Bridge mills derive their name from the bridge-shaped beam that spans the work area. The key components of a bridge mill are: ● Bridge - The large overhead beam that supports the spindle slide and provides damping against vibrations. It contains the mechanisms to position the spindle in X and Y. ● Spindle - The rotating shaft that holds the cutting tool. It is powered by a motor inside the spindle slide with up to 50 hp. High torque spindles allow fast removal of material. ● Table - The large stationary or moving platform that supports the workpiece. It provides a precision mounting surface and T-slot holds for clamps and fixtures. ● Column - A fixed vertical member at one end that helps support the bridge. The column may house controls or services. ● Saddle - The moving transverse component mounted to the underside of the bridge. It positions the spindle slide in the Y-axis across the width of the table. ● Spindle Slide - The carriage assembly that traverses back and forth along the bridge in the X-axis, positioning the spindle over the workpiece. Compared to gantry or knee mills, bridge mills are significantly heavier and bulkier, with a main bridge that is much more rigid thanks to its continuous cast iron or welded steel overhead design. This mass and stability is crucial for absorbing cutting forces and dampening vibration that could compromise precision. The rigid construction also minimizes deflection of the spindle during aggressive material removal, enabling much tighter tolerances. When machining large components made of tough materials like steel or titanium, the stability of a bridge mill is vital to achieve chatter-free results. Their overhead configuration also allows practically unlimited workpiece sizes.   Types of Bridge Mills   Bridge mills are available with different axis configurations and levels of automation to suit a wide range of applications: 2-Axis Bridge Mills The simplest bridge mill design has two linear axes allowing motion in the X (longitudinal) and Y (transverse) directions. This provides positioning of the workpiece beneath the spindle for basic 2D operations like facing, drilling, boring, and end milling of flat surfaces. While limited in versatility, 2-axis bridge mills are an affordable option for high-volume production of large but basic parts, as their range of motion is sufficient for straightforward machining. 3-Axis Bridge Mills A 3-axis bridge mill adds a Z-axis that raises and lowers the spindle vertically. This permits angled milling operations like helical interpolation, allowing the machining of bevels, tapers, contours, and angled features. The additional axis provides the ability to machine in 3 dimensions instead of just 2. Manufacturers gain greater flexibility to produce more complex components with a 3-axis bridge mill. 5-Axis Bridge Mills On a 5-axis bridge mill, the spindle head tilts and rotates on two additional rotary axes in addition to moving linearly in X, Y, and Z. This enables the spindle to approach the workpiece from practically any orientation rather than just vertically. 5-axis motion facilitates high-precision machining of complex 3D surfaces and contours in a single setup, saving tremendously on time and cost. Many aerospace and impeller components require 5-axis milling due to their intricate blended or sculpted geometries. Automated Bridge Mills Modern computer numerical control (CNC) bridge mills allow all machining operations to be precisely programmed ahead of time. This allows push-button automation of repetitive cutting procedures with minimal operator intervention. The computer control precisely choreographs and executes tool paths for mass production. Automated tool changers, pallet changers, and robotic part load/unload systems can further enhance productivity for lights-out manufacturing across multiple shifts.   Key Features and Components of Bridge Mills  Massive Work Area The cantilevered overhead design of a bridge mill leaves the entire area beneath the spindle open for oversized parts and assemblies. Common table sizes range from 5 x 10 ft up to 20 x 60 ft for gigantic components weighing over 100 tons. Huge motors drive the table through precision roller or hydrostatic ways. This expansive work zone minimizes setups by allowing batch machining of multiple large parts or entire weldments in a single fixture. Rigid Bridge Assembly Weighing up to 100,000 lb, the continuous overhead bridge utilizes a rigid box-way construction that resists deflection and damps vibration far better than jointed column or gantry mills. This stability prevents tool chatter, allows heavier cuts, and enables highly accurate motion of the spindle carriage across wide spans. Even minimal vibration can degrade precision and surface finish. Powerful Spindles High torque spindles up to 50 hp are common on bridge mills to power through hard alloys and remove material quickly from large parts. Higher rotational speeds up to 15,000 rpm provide ideal cutting speeds for optimized tool life and surface finish. The spindle cartridge is preloaded for thermal stability and minimal runout. Precise Positioning Ballscrews on the X, Y, and Z axes have high lead precision for accurate positioning and repeatability within 0.001”. Backlash is eliminated through preloading. Precision ground box ways or linear guides maintain tight geometrical tolerances when moving heavy components. Multi-axis Capability Optional rotary axes expand the range of possible milling operations by allowing angled cuts and 5-axis interpolated motion. Tilting the spindle facilitates machining of complex 3D contours, sculpted surfaces, and intricate blade geometries in a single setup. Automated Features Bridge mills equipped with CNC, tool changers, pallet shuttles, robotic part handling, automatic lubrication, and more enable lights-out manufacturing for maximum productivity. Hundreds of parts can be machined without operator intervention across multiple shifts.   Applications of Bridge Mills   Aerospace Industry Aircraft construction relies on large monolithic components like wings, frames, and bulkheads milled from aluminum, titanium, or composites. Landing gear, turbines, transmission housings, and other assemblies also demand high precision. Bridge mills offer the work envelope and accuracy needed for these high-value aerospace components with delicate instrumentation. Automotive Industry Automakers machine engine blocks, cylinder heads, crankshafts, transmission cases, axles, wheels, and body components from large steel or aluminum castings and weldments. Bridge mills maintain tight tolerances on these heavy parts while removing material quickly. Their high rigidity suits the noisy environment. Heavy Machinery Massive excavator booms, bulldozer track links, hydraulic cylinders, press frames, and other oversize parts require stable bridge mills to withstand vibrations inherent in heavy machining. They excel at removing substantial material from thick castings and fabrications. Mold Making Larger injection molds, die cast dies, and foundry patterns demand the precision of bridge mills to accurately produce contoured cavities without distortion. Their work volume readily accommodates even enormous 400-ton plastic or metal molds. Tight process control optimizes molded part quality. Energy Industry Turbines, compressors, reactors, valves, offshore platform components, and more leverage the long travels and precision of bridge mills during manufacturing. The mills maintain quality standards for these expensive parts operating in extreme conditions.   Benefits of Using Bridge Mills Precision The stability provided by the rigid overhead bridge enables extremely tight tolerances, even when machining large parts from vibration-prone materials like titanium or nickel alloys. Chatter is avoided, allowing smooth, accurate cuts. Versatility Available in different sizes and with varying axis configurations, bridge mills can handle a wider range of materials and part geometries compared to smaller mills. Their heavy-duty build allows machining everything from stainless steel to composites. Cost Savings While bridge mills require a greater upfront investment, they maximize productivity and minimize operating costs on large components. Their ability to consolidate several operations in one setup saves tremendously on fixtures, tooling, programming, and quality inspections. Improved Throughput Continuous cuts across expansive work zones result in shorter cycle times. Pallet changers and part loading/unloading automation further boost throughput for high-volume production across multiple shifts, improving asset utilization. Reliability Industrial bridge mills are built for round-the-clock operation in harsh conditions. They stand up to heavy use with minimal downtime. Many operate reliably for decades after proper installation, maintenance, and training.   How to Choose the Right Bridge Mill Workpiece Size Consider current and future maximum part dimensions to ensure the mill will accommodate them with room for fixturing and tooling. A too-small machine will severely limit capability. Axis Configuration The type and complexity of required milling operations determines the ideal number of axes. 5-axis mills offer the most application flexibility and reduce setups through multisided machining but are costlier. Spindle Power Ample spindle power prevents slowdowns or stalling when removing substantial material. Higher torque spindles with 15,000+ rpm allow faster hogging and finishing feeds/speeds. Ensure power meets demands. Precision Standards More expensive machines generally offer greater accuracy through more precise ballscrews, way quality, vibration dampening, and thermal stability. Evaluate precision needs carefully. Automation Plans Consider pallet changers, robotic part handling, tool changers, CNC programming, and other automation upfront rather than difficult retrofitting later. This optimizes lights-out production. Service and Support Reliable local service and technical support will maximize uptime and productivity. Ensure the machine builder has a proven reputation for quality and customer care.   Common Challenges with Bridge Mills  Vibration Control Excessive vibration during heavy duty milling can cause chatter, accuracy issues, poor surface finish, and reduced tool life. Careful fixturing, balanced tooling, adaptive feed control, and smooth ramping of spindle speed help mitigate vibrations. Thermal Effects Frictional heat during machining causes components to expand, altering dimensions. Chillers and coolant systems counteract thermal growth. CNCs can also compensate by altering cutter paths based on temperature sensors. Tool Wear Abrasive alloys quickly degrade cutting tools. Advanced tool materials, coatings, proper selection of speeds/feeds, and indexed inserts all help combat wear. In-process gauging can automatically adjust for loss of tool diameter. Maintenance Needs Bridge mills have thousands of moving components requiring regular lubrication, inspection, and service for optimal reliability. Skilled technicians should track and perform preventative maintenance. Space Constraints Bridge mills have massive footprints, heights, and weights demanding substantial floor space, reinforced foundations, and rigging equipment. Facilities must carefully plan layouts to accommodate their bulk.   Future Trends in Bridge Mill Technology Automation and AI Integration Smart machine monitoring with artificial intelligence promises even greater productivity through predictive maintenance, troubleshooting, adaptive control, and automated inspection. The mills will become self-optimizing. Multi-tasking Capability Next-generation bridge mills will incorporate turning, grinding, drilling, tapping, and other capabilities on one platform for complete production of complex parts in a single setup. Hybrid machine tools will continue gaining traction. Advanced Materials More manufacturers are adopting hard-to-machine materials like titanium, Inconel, and composites. Future spindles, tools, programming, and controls will be optimized for these exotic materials. Sustainable Design Eco-friendly lubrication systems, intelligent sleep modes, hybrid drives, and through-spindle coolant will be incorporated for energy and fluid efficiency. Bridge mills are getting greener.   Conclusion Bridge mills with their huge work areas, superb stability and multi axis flexibility allow manufacturers to increase precision, productivity and agility when making large complex parts. They are leaders in optimizing output, quality and consistency for critical aerospace, automotive and heavy industry parts. Bridge mills are a greater upfront investment, but the long term savings of reduced setups, improved workflow and increased throughput are huge. Bridge mills will only grow in strategic importance as engineering components become bigger and more sophisticated. Strong consideration should be given by companies seeking to maximize manufacturing capabilities, capacity, and competitiveness to the use of bridge mills. Their advantages are unique, enabling manufacturers to do what is not possible on smaller machines.

Curved guides and linear guides are two common types of guides. Both have support and guidance functions. Both can transfer the energy of movement to the receiving end to achieve stable movement. So what is the difference between the two? From a structural point of view, linear guides are in the shape of a straight line, and they play a role in positioning, supporting and guiding in the movement of machinery and equipment. Curved guides are a special circular structure that is widely used in hardware, automation and precision mechanical equipment, and can maintain the axis position of relative movement unchanged. From the perspective of motion trajectory, the movement mode of linear guides is linear motion driven by balls. The contact area between the balls and the guide grooves is small, so that the surface of the guide is evenly stressed and has a long life cycle. The arc guide realizes movement by the rolling of the balls on the curved surface of the guide. The curved surface of the guide bears a larger contact area, so the load capacity is higher than that of linear guides.   From the application point of view, linear guides are widely used in CNC machine tools, semiconductor equipment, medical equipment and other fields due to their linear motion characteristics. They can provide high-precision, high-rigidity and low-friction motion control, and are suitable for high-speed and high-precision linear motion requirements. Curved guides are more suitable for occasions that require curved motion or circular interpolation, such as robots, aerospace equipment, precision measuring instruments, etc. They can achieve smooth curved motion and precise circular interpolation, improving the motion performance and positioning accuracy of the equipment. The above is the difference between linear guides and circular guides. When choosing guides, users in the machinery industry should choose the appropriate guide form according to the specific usage scenarios and needs to ensure the stability and reliability of the mechanical equipment.

We are specializing in the production of metal scrap shear for metal recycling. Our container shear machine is horizontal type and it's suitable for cutting metals with different cross-sectional shapes in the cold state. Horizontal automatic container shear is very suitable for cutting metals of different cross-sectional shapes in cold state, such as round, square, slot, angle, I-shaped, plate and various scrap structural metals. It brings convenience to the packaging, storage and transportation of scrap metal materials, and also provides qualified furnace charge for smelters. Features:   The box shear machine has a wide range of applications and is a processing equipment for metal recycling stations, factory foundries and mechanical construction industries.   1.Container machine adopts hydraulic drive, you can choose manual or PLC automatic control operation. Automatic control can save human energy. 2.Production capacity up to 15 -20tons per hour 3.Eco friendly no gases required. 4.HARDOX is used as wear resistant plates 5.Blades are made up of graded tool steel for high wear resistance and long life.The scrap feed in hopper, due to the movement of pre clamp the scrap automatically slips down and the cut scrap is pushed out from the front. 6.Continuous raw material feed 7.Lesser space required. 8.The installation does not require any foundation or foot screw.

Hydraulic alligator shears are essential in various industrial fields such as scrap metal processing and manufacturing. Regular maintenance is essential to ensure the life and effectiveness of key components. This article provides a detailed guide on maintaining and servicing the main components of hydraulic alligator shears.   1. Maintaining the cutting blade Regular inspection and sharpening: Regularly check the blade for dullness or damage. Sharpen the blade as needed to ensure smooth cutting and relieve stress on the machine. Replacement: If the blade is excessively worn or damaged, replace it in time to avoid affecting the efficiency and safety of the machine. 2. Press cylinder The press cylinder is responsible for the driving force of the shear to cut the material. Seal inspection: Frequently check the hydraulic seal for wear or leakage. If necessary, replace the seal to prevent fluid leakage and maintain pressure. Rod condition: Check for wear, corrosion or misalignment on the cylinder rod. A damaged rod can lead to inefficient operation and safety hazards. 3. Press plate The press plate holds the material in place during the cutting process. Alignment check: Make sure the press plate is aligned with the cutting blade for optimal performance. Surface inspection: Check regularly for any cracks or wear, and repair or replace the platen if it is damaged. 4. Motor The motor powers the hydraulic pump and needs to be checked regularly to ensure it is operating efficiently. Cooling system: To prevent overheating, keep dust and debris out of the motor's cooling system. Electrical connections: Check all electrical connections for signs of wear or corrosion. Secure any loose connections and replace damaged wires or components. 5. Valves The pressure and flow of the hydraulic oil are managed through hydraulic valves. Operational testing: To ensure the valves are operating properly, test them regularly. Be alert for unusual sounds that may indicate potential problems. Cleaning: Keep the valves clean and free of debris buildup that can cause the valves to stick or malfunction 6. Cutting cylinders Like press cylinders, cutting cylinders are used for cutting, so similar care is required. Leakage checks: Make sure the hydraulic oil level is correct and perform regular leak checks. Pressure tests: Check the hydraulic pressure in the cutting cylinder regularly to ensure it meets the specifications required for efficient operation. 7. Pumps The machine's hydraulic oil must move, so a hydraulic pump is needed. Oil Level and Quality: Check the hydraulic oil level regularly and top up as needed. Replace the oil if it is contaminated. Pump Inspection: Listen for noise changes and check for vibrations, which may indicate wear or misalignment. 8. Electric Box The electric box contains the electrical components that control the machine. Moisture and Dirt: Make sure the electric box is free of moisture and dirt, which can cause electrical failures. Component Inspection: Frequently check all components inside the electric box for signs of wear or damage. Replace any damaged components immediately. 9. Oil Tank The oil tank stores the hydraulic oil required for the machine to operate. Cleanliness: Keep the oil tank clean and ensure that the oil is not contaminated by debris or water, which can damage the hydraulic system. Gaskets and Seals: Check the seals and gaskets that attach to the oil tank for signs of degradation or perforation and replace them accordingly. 10. General Maintenance Tips Routine Cleaning: Clean the entire machine regularly to prevent the accumulation of debris and dirt, which can affect the operation of the machine and cause premature wear. Lubrication: Apply lubricant to moving parts as directed by the manufacturer to ensure seamless function.   Regular maintenance is essential to the life, efficiency and safety of hydraulic alligator shears. Regular inspection and maintenance of components such as cutting blades, cylinders, motors and valves prevents breakdowns and optimizes performance.

TEYUN Horizontal balers are used for recycling of waste paper, plastics, PET bottles and cans. This series of balers can be configured with hoppers and can be fed with conveyors or manually according to customer needs. We can also provide engineering design and help to simplify customers' work and improve overall efficiency. Advantages The wide hopper opening is suitable for large and hollow materials. The hydraulic drive has the advantages of stable operation, high pressure and high efficiency. Good appearance, compact structure, high efficiency, simple operation, safe and reliable. The baling size can be built according to customer requirements!   Horizontal baler is also known as carton baler, waste paper strapping machine, waste paper processing equipment, the equipment is used in the normal state of waste paper and similar products extruded firm, and packaged with a special packaging tape molding, so that its volume is greatly reduced, so as to achieve the purpose of reducing the volume of transportation, saving freight costs, and increase the benefits for the enterprise. The company's waste paper baler and carton strapping machine processing equipment introduces the advanced technology and advanced process of similar products at home and abroad.   Advantages of waste paper horizontal baler: Waste paper horizontal baler has good rigidity and stability, beautiful and generous modeling, easy to operate and maintain, safe and energy-saving, low investment cost of equipment infrastructure projects and so on. It is widely used in all kinds of waste paper factories, old things recycling company and other units of enterprises, suitable for the old waste paper, plastic straw and other baling and recycling, is to improve labor efficiency, reduce labor intensity, save manpower, reduce transportation costs of good equipment.

  The following is the first part of the daily operation and maintenance of slurry pumps： tart-up and shutdown： Preparations Before Start-up： Check whether the connecting bolts and foundation bolts of the pump are loose. Check whether the piping connection is proper and whether the centers of the pump and the driver are aligned. For pumps handling high-temperature or low-temperature liquids, the expansion and contraction of the piping may cause shaft misalignment, seizure, etc. Therefore, flexible pipe joints, etc., should be used. Direct coupling and alignment. For small-sized pumps handling normal-temperature liquids, there is no problem in aligning the pump and the motor when the pump is stopped. However, for large-sized pumps handling high-temperature liquids, there is a large difference in the shaft center during operation and stoppage. To achieve correct alignment, generally heat to the operating temperature or stop the pump after the operation and quickly re-align to ensure that the shaft centers of both rotating parts are the same and avoid vibration and pump seizure. Clean the piping. Before operation, the piping must be cleaned first to remove foreign objects, welding slag, etc. from the piping. Do not let foreign objects or welding slag fall into the pump body. Install pressure gauges before and after the strainer in the suction pipe to monitor the clogging of the strainer during operation. Barring. Remove the coupling before start-up, turn the rotor by hand to observe whether there are any abnormal phenomena, and conduct a separate test run of the motor to check whether its rotation direction is the same as that of the pump. By rotating the coupling by hand, it can be found whether there are foreign objects between the impeller and the casing inside the pump. The barring should be even in weight, and there should be no abnormal noise inside the pump. Start the oil pump and check whether the bearing lubrication is good. Priming the pump. Fill the pump chamber with liquid before start-up to discharge air, liquefied gas, and steam from the suction pipe and the pump body. Start-up： The idle operation must be avoided. At the same time, open the suction valve, and close the discharge valve and each discharge hole. Open the cooling water supply valve for the bearings. If the stuffing box has a water jacket, open the cooling water supply valve of the stuffing box. If the pump handling high-temperature liquid has not reached the working temperature, open the preheating valve, and close this valve after the pump is preheated. If the pump is equipped with a liquid-sealing device, open the valve of the liquid-sealing system. If equipped with an overheating device, open the bypass valve of the self-circulation system. Start the motor. When the pump flow increases and overheating is no longer possible, close the valve of the self-circulation system. If the pump must be started with the check valve closed and the outlet gate valve open, the start-up steps are basically the same as the above method, except that the outlet gate valve should be opened for a period of time before the motor is started. Gradually open the discharge valve. Shutdown： Open the valve on the self-circulation system. Close the discharge valve. Stop the motor. If it is necessary to maintain the working temperature of the pump, open the preheating valve. Close the cooling water supply valves of the bearings and the stuffing box. If liquid-sealing is not required during the shutdown, close the liquid-sealing valve. If it is a special pump device requirement or when the pump is opened for inspection, close the suction valve, and open the vent hole and various discharge holes. Usually, the start-up and shutdown steps specified for turbine-driven pumps are basically the same as those for motor-driven pumps. Turbines have discharge valves, various drain holes, and sealing devices, which must be opened or closed before and after operation. In addition, turbines generally require preheating before start-up. Some turbines in the system are required to be started at any time, so barring operation is required. Therefore, the operator should operate according to the relevant regulations on the start-up and shutdown steps of the turbine provided by the turbine manufacturer. Maintenance During Shutdown For standby pumps at the chemical plant site, when the in-use pump fails, they should be able to be switched over in time and put into normal operation to ensure that the chemical production process is not interrupted. This requires the maintenance of the standby pumps to keep them in good condition during the standby and shutdown period. Especially for standby pumps with interlock and automatic switching, their inlet and outlet valves are open, and the pumps are filled with the medium to be transported. As long as the driver rotates, they can start working immediately. For standby pumps during the shutdown period, the quality and quantity of the lubricant should be checked frequently. The pump body and the medium inside the pump that needs to be heated and insulated should be heated and insulated. To prevent the rotor from bending due to its own weight and to prevent the shaft from adhering to the bearings and causing start-up difficulties, the standby pumps should be barring regularly. For pumps that have been shut down for a long time, open the plugs on the pump body to drain the liquid inside the pump to avoid damage to the pump body due to cold weather. If necessary, open the pump body, clean the internal parts, and apply anti-rust oil. For pumps that have been shut down for a long time, whether they are on-site or in the warehouse, they should be barring regularly. For details of the first part, please refer to the next blog post.

Lubrication: During the operation of a slurry pump, the possible intrusion of the conveyed medium, water, and other substances into the oil tank may affect the pump's normal operation. Therefore, it is necessary to check the quality and oil level of the lubricant frequently. The quality of the lubricant can be observed with the naked eye and analyzed by regular sampling. The amount of lubricating oil can be seen from the oil level mark. For a new pump, the oil should be changed once after one week of operation. For a pump with replaced bearings during overhaul, the oil should also be changed. Because foreign substances enter the oil during the running-in of the new bearings and shafts, the oil must be changed. Thereafter, the oil should be changed once every quarter. The lubricating grease and lubricating oil used for chemical pumps should meet quality requirements. Tables 2-8 and 2-9 show the commonly used lubricating grease and lubricating oil for slurry pumps. Vibration: During the operation of the pump, due to reasons such as poor quality of spare parts and maintenance, improper operation, or pipeline vibration, vibration often occurs. If the vibration exceeds the allowable value, the pump should be shut down for maintenance to prevent damage to the machine. Table 2-10 shows the allowable range of vibration values for slurry pumps. Bearing temperature rise: During the operation of the pump, if the bearing temperature rises rapidly and after the temperature rise stabilizes, the bearing temperature is too high, which indicates that there are problems in the manufacturing or installation quality of the bearing; or the quality, quantity, or lubrication method of the bearing lubricating oil (grease) does not meet the requirements. If not dealt with in time, the bearing is in danger of being burned out. The allowable temperature for slurry pump bearings is <65°C for sliding bearings; and <70°C for rolling bearings. This allowable value refers to the allowable range of bearing temperature after running for a period of time. For a newly replaced bearing, at the initial stage of operation, the bearing temperature will rise relatively high. After running for a period of time, the temperature will drop somewhat and stabilize at a certain value. The operating performance of slurry pump: During the operation of the pump, if there is no change in the liquid source and the opening degree of the valves on the inlet and outlet pipelines remains unchanged, but the flow rate or inlet and outlet pressure changes, it indicates that there is a fault in the pump or pipeline. The cause should be quickly identified and eliminated in time, otherwise, adverse consequences will be caused. The size of the system resistance can be achieved by adjusting the opening degree of the inlet and outlet valves of the pump. For a determined pump system, when the outlet valve is fully opened, the system resistance is the smallest, and the corresponding flow rate is the largest, the head is the smallest, and the power is the largest. When the outlet valve is completely closed, the system resistance reaches a maximum value. At this time, the flow rate is zero, the head is the largest (a finite value), and the power is the smallest. From this, the following points can be summarized: When starting a slurry pump, in order to avoid overloading the prime mover, the outlet valve should be closed first and then opened slowly after the pump is started. In this way, it can avoid the superposition of the large starting load of the prime mover and the high power required by the pump when the outlet valve is fully opened, which may cause overloading of the prime mover. As long as the pump chamber is filled with liquid (to avoid dry friction of the sealing ring, shaft seal, etc.), the slurry pump is allowed to operate for a short time when the outlet valve is closed. Except for the rapid temperature rise of the limited liquid in the pump chamber under the action of the rotating impeller, which has some adverse effects on the pump, there is no adverse effect on the prime mover. At this time, the load on the prime mover is the lightest. During operation, any set of flow rates and heads within the performance range of the slurry pump can be obtained by adjusting the opening degree of the outlet valve. However, when the pump operates at the design operating point, its efficiency is the highest; the farther away from the design operating point, the lower the efficiency. Unit sound: The sounds emitted by the pump during operation are some normal and some abnormal. For abnormal sounds, find out the cause and eliminate it in time. The following are roughly the reasons for the abnormal sounds of the pump. Reasons on the fluid side: For example, insufficient inlet flow of the slurry pump causes cavitation and emits noise; air accumulation in the pump outlet pipeline causes water hammer and emits an impact sound. Reasons on the mechanical side: The bearing quality does not meet the requirements or is damaged; the clearance between the moving and stationary parts of the pump is inappropriate, causing friction; shaft bending causes internal friction; parts are damaged and fall off; foreign objects fall into the pump, etc.   For details of the first part, please refer to the previous blog post.

Chemical Industry: Transporting corrosive liquids: It can be used to transport strong acids such as hydrochloric acid, sulfuric acid, and nitric acid, as well as strong alkali solutions like sodium hydroxide. In the production process of various chemical fertilizers, fluorides, etc. in chemical production, magnetic pumps are also often used to transport relevant media. At this time, chemical-resistant magnetic pumps are required. Transporting flammable and explosive liquids: Such as gasoline, methanol, toluene, and other organic solvents. Magnetic pumps have no mechanical seal and will not generate friction sparks, which can ensure the safety of the transportation process and reduce the risk of fire and explosion accidents. At this time, organic solvent transfer magnetic pumps are needed. Participating in chemical reactions: In some chemical reactions that require the cyclic transportation of reaction liquids, magnetic pumps can stably provide power to ensure the smooth progress of the reaction, for example, in the cyclic process of gas-absorbing reaction liquid. At this time, stainless steel chemical process magnetic pumps are needed. Pharmaceutical Industry: Liquid medicine transportation: It is used to transport various liquid medicines, slurries, biological drugs, etc. Its leak-free and pollution-free characteristics can ensure the purity and quality of drugs, and ensure the stability and safety of drugs, meeting the strict requirements of pharmaceutical production. At this time, sanitary magnetic drive centrifugal pumps are required. Pharmaceutical equipment support: In some pharmaceutical equipment, such as washing machines, reactors, etc., magnetic pumps need to be used in conjunction with transport media to meet the fluid transportation requirements in the pharmaceutical process. At this time, stainless steel chemical process magnetic pumps are needed. Food Industry:  In the fields of food processing and beverage production, magnetic pumps can be used to transport food raw materials or finished products such as fruit juice, milk, and syrup. Since there are no leak-prone or liquid-contacting parts, it will not cause secondary pollution to food, can maintain the original taste and quality of food, and improve the food hygiene standard. At this time, sanitary magnetic drive centrifugal pumps are required.   Electronic Industry:  It is mainly used to transport corrosive liquids, pure water, and other media. In the electronic production process, the purity and cleanliness of the media are required to be extremely high. Magnetic pumps have no seals, which can avoid liquid leakage and damage to electronic equipment, and can also meet the high requirements of the electronic industry for media. At this time, fluoroplastic anti-corrosion magnetic pumps are required.   Electroplating Industry:  It is suitable for the transportation and cyclic filtration of various electroplating solutions, such as chrome-plating solutions, nickel-plating solutions, zinc-plating solutions, etc. Magnetic pumps can run stably in the harsh environment of the electroplating process, ensure the accurate transportation of electroplating solutions, and improve the efficiency and quality of electroplating production. At this time, polyvinylidene fluoride (PVDF) material magnetic-driven pumps are required.     Petrochemical Industry: Crude oil transportation: In the process of oil exploration and transportation, crude oil and its associated media can be transported. Its good sealing and reliability can ensure the safety and efficiency of oil production. At this time, three-screw magnetic-driven pumps are required.   Refining process: In the refinery unit, it is used to transport various high-temperature, high-pressure, and corrosive media, such as transporting relevant liquids in the process of catalytic cracking, hydrocracking, etc. At this time, CQG - G series high-temperature and high-pressure magnetic pumps are required.     Mining Industry: Metal smelting: It is used to transport electrolytes in the metal smelting process and wash the waste liquid generated during the smelting process, which helps to improve the efficiency and environmental protection of metal smelting. At this time, polyvinylidene fluoride (PVDF) material magnetic-driven pumps are required.   Mineral processing: In the mineral processing process, it can transport various slurries, acid solutions, and other media, providing fluid transportation support for each link of mining production. At this time, high-chromium alloy magnetic-driven pumps are required.

The dynamic seal of a centrifugal pump is a sealing method that relies on the centrifugal force of rotating components, and it can be divided into two categories: back-blade seal and auxiliary impeller seal.   Back - blade seal: (1) Structure: Blades are added to the rear cover plate of the impeller of the centrifugal pump, and these blades rotate in the opposite direction to the impeller. These blades are back-blades. (2) Working principle: When the centrifugal pump is in operation, the rotation of the impeller drives the back blades to rotate together. The centrifugal force generated by the rotation of the back - blades will throw the liquid at the rear cover plate of the impeller to the outer periphery of the impeller, reducing the liquid pressure at the rear cover plate of the impeller and forming a low-pressure area. As a result, it is difficult for the high-pressure liquid at the impeller outlet to leak through the gap between the impeller and the pump casing to the low-pressure area, thus achieving the sealing effect. (3) Advantages: The structure is relatively simple, no additional complex devices are required, and the cost is low; it can balance the axial force of the centrifugal pump to a certain extent, reduce axial movement, and improve the operation stability of the pump. (4) Disadvantages: The sealing effect is relatively weak, and it may not be suitable for some occasions with very high sealing requirements; the presence of back-blades will increase the frictional resistance of the impeller, resulting in a slight reduction in the pump's efficiency.   Auxiliary impeller seal: (1) Structure: It usually consists of an auxiliary impeller, auxiliary blades (also called back-blades), fixed guide vanes, and a shutdown sealing device. The auxiliary impeller is a small centrifugal pump impeller, which rotates coaxially with the working impeller of the centrifugal pump. (2) Working principle: During operation, the liquid leaked from the working impeller of the centrifugal pump flows to the auxiliary impeller. The centrifugal force generated by the rotation of the auxiliary impeller forms a pressure head, which can resist the high-pressure liquid at the outlet of the working impeller from leaking out, thereby achieving the sealing purpose. When the pump is shut down, the dynamic seal of the auxiliary impeller does not work. The liquid pressure inside the pump is small, and the liquid leaked to the auxiliary impeller is sealed by the shutdown sealing device. For example, three oil seals and one water-blocking ring are used for sealing. (3) Advantages: The sealing effect is relatively good, and it is suitable for conveying media containing certain impurities because the influence of impurities on the auxiliary impeller is relatively small; during the operation process, the centrifugal force generated by the auxiliary impeller can also play a certain stirring role to prevent the precipitation of the medium. (4) Disadvantages: The rotation of the auxiliary impeller consumes a certain amount of energy, which will increase the power consumption of the pump; the processing accuracy requirements of the auxiliary impeller are relatively high, and the manufacturing difficulty is relatively large.   The dynamic seals produced by Anhui Changyu Pump and Valve Manufacturing Co., Ltd. are all made of fiberglass - reinforced plastic. Due to the relatively low density of fiberglass - reinforced plastic, when the back - blades rotate, at the same rotational speed, their moment of inertia is relatively small. This means that during the starting and stopping processes, the back - blades need to overcome less inertial force and can reach a stable operating state or stop more quickly. From the perspective of the sealing principle, the fiberglass - reinforced plastic back - blades are stable in performance when the centrifugal force generated by rotation throws the liquid at the rear cover plate of the impeller to the outer periphery. Moreover, the good corrosion resistance of fiberglass - reinforced plastic can prevent changes in the blade surface caused by liquid corrosion, thereby maintaining the formation of a low - pressure area stably for a long time and ensuring the sealing effect. For example, in the working condition of transporting a mixed solution of acid, alkali, and salt with a certain concentration, the fiberglass - reinforced plastic back - blades can maintain the sealing performance more effectively compared with metal back - blades and reduce the situation of seal failure caused by corrosion.   The mechanical seal of a centrifugal pump is a high-performance sealing method. The following is a detailed introduction: Structural composition (1) Rotating ring and stationary ring: The rotating ring rotates with the pump shaft, and the stationary ring is fixed on the pump body and remains stationary. They are the key sealing elements of the mechanical seal. They are usually paired with hard materials (such as tungsten carbide, ceramic, etc.) and soft materials (such as graphite, impregnated graphite, etc.). The end faces of these materials are finely ground with extremely high flatness. For example, in some high-temperature and high-pressure application scenarios, the combination of tungsten carbide and graphite is often used. Tungsten carbide has high hardness and good wear resistance, and graphite has good self-lubricating properties and chemical stability. (2) Spring: The spring provides the axial pre - tightening force for the mechanical seal to ensure that the end faces of the rotating ring and the stationary ring are always in close contact during the operation of the centrifugal pump. There are various types of springs, including single-spring and multi-spring forms. The single-spring structure is simple, but the force is unevenly distributed; the multi-spring can make the force distribution more uniform and is suitable for high-speed centrifugal pumps. (3) Sealing ring: It is used to seal the gaps between the rotating ring and the shaft, the stationary ring and the gland, etc., to prevent liquid from leaking from these parts. The material of the sealing ring is selected according to different working conditions. Common materials include rubber (such as nitrile rubber, fluorine rubber, etc.) and polytetrafluoroethylene. For example, when transporting acidic media, fluorine rubber sealing rings can be selected because of their good acid resistance.   Working principle During the operation of the centrifugal pump, the spring force and the liquid pressure act on the rotating ring together, making the end faces of the rotating ring and the stationary ring closely contact to form an extremely thin liquid film. This liquid film has a sealing effect and can also lubricate and cool the end faces. Since the rotating ring rotates with the shaft and the stationary ring is fixed, the existence of the liquid film can reduce friction and wear when the two are in relative motion, when the pressure inside the pump changes, the change in liquid pressure will also affect the sealing force between the rotating ring and the stationary ring, thus ensuring the sealing performance under different working conditions. Advantages (1) Good sealing performance: The leakage of the mechanical seal is extremely small, which can effectively prevent the liquid inside the pump from leaking. It is very suitable for some occasions with strict leakage requirements (such as centrifugal pumps for transporting toxic, flammable, and explosive media). (2) Long service life: The high-quality materials of the rotating ring and the stationary ring and the reasonable structural design enable the mechanical seal to operate stably for a long time under normal working conditions, reducing the trouble of frequent seal replacement. (3) Adapt to various working conditions: It can adapt to complex working conditions such as high temperature (some mechanical seals can work in a high-temperature environment of several hundred degrees), high pressure (the pressure can reach several megapascals or even higher), and high speed (high - speed centrifugal pumps), and has good sealing effects for clean media and media containing a small amount of impurities. (4) Low power loss: Since the liquid film between the rotating ring and the stationary ring plays a good lubricating role and the friction coefficient is small, compared with the packing seal, the power loss of the mechanical seal is lower, which is beneficial to improving the operation efficiency of the centrifugal pump.   Disadvantages (1) Complex structure: The mechanical seal has many components, and the structure is relatively complex, with high requirements for design, manufacturing, and installation. For example, the parallelism of the end faces of the rotating ring and the stationary ring is strictly required, and a slight deviation during the installation process may affect the sealing performance. (2) High cost: The high-quality materials of the rotating ring and the stationary ring are expensive. Coupled with the precision processing technology and complex assembly requirements, the cost of the mechanical seal is much higher than that of other sealing methods such as the packing seal. (3) Sensitive to impurities: If the medium contains more solid impurities or particles, the impurities may enter between the end faces of the rotating ring and the stationary ring, scratching the sealing surface and causing the seal to fail. Therefore, there are certain requirements for the cleanliness of the medium.   The mechanical seals produced by Anhui Changyu Pump and Valve Manufacturing Co., Ltd. have good sealing performance, long service life, can adapt to various working conditions, low power loss, and high processing precision. With strict factory - out inspection, the superior performance of the mechanical seals is ensured.